Question

Solve the equation.
cos 2x = 0

Answer 1

hii...

there's the solution...
have a look at it




AND BY THE WAY
I FORGOT
TODAY IS CHILDREN'S DAY

HAPPY CHILDREN'S DAT DEAR☺☺☺

Answer 2

Solution:
➖➖➖

As we know that principal value branch of cos inverse is [0,π]

thus while solving the equation we must remember that cos inverse cancel cos x only if x belongs to principal value branch.

we know that cos π/2= 0

$cos 2x= 0\\ \\ 2x= {cos}^{-1}(0) \\ \\ 2x = {cos}^{ - 1} (cos (\frac{\pi}{2}))$

here both cancels with each other because π/2 belongs to [0,π]

Thus

$2x = (\frac{\pi}{2})\\\\ x= (\frac{\pi}{4})$